Modeling and Stability Analysis of Prototype Mixed Kinematic Bulk, Free Surface, and Interfacial Flows of Viscoelastic Fluids

粘弹性流体的原型混合运动体积流、自由表面流和界面流的建模和稳定性分析

• 批准号: 9612499
• 负责人: Bamin Khomami
• 金额: $ 24.5万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9612499&HistoricalAwards=false
• 关键词: Modeling; Stability; Analysis; Prototype; Mixed

This is a grant to address problems related to polymeric and polymer matrix composite materials that have been identified as being key to the security of the U.S. The basic part of most polymer and composite materials manufacturing processes involves flow of polymers in cavities of arbitrary shape with or without reinforcement. Process throughput and product quality are often limited by the onset of flow instabilities. The existence of purely elastic instabilities suggest that all polymer processing operations, however slow they may be, are prone to instabilities. For this reason understanding the influence of fluid elasticity on flow and stability of representative bulk, free surface and interfacial flows is crucial. Fully parallelized, higher-order finite element techniques will be used to study a number of prototype two and three-dimensional free surface and interfacial flows of viscoelastic fluids. Specifically, the work will focus on investigating flow modifications due to fluid elasticity in mixed shearing/elongational flows as well as examining the role of fluid elasticity and non-equilibrium energetic effects on stability of this class of flows. Of particular interest is to identify the mechanism(s) that are responsible for viscoelastic instabilities in mixed kinematic flows which are routinely encountered in processing of polymers and composite materials.

这笔赠款旨在解决与聚合物和聚合物基复合材料相关的问题，这些材料已被认为是美国安全的关键。大多数聚合物和复合材料制造工艺的基本部分涉及聚合物在任意形状的空腔中的流动，其中具有或没有加固。 工艺产量和产品质量通常受到流动不稳定的影响。 纯粹弹性不稳定性的存在表明，所有聚合物加工操作，无论有多慢，都容易出现不稳定。 因此，了解流体弹性对代表性体积流、自由表面流和界面流的流动和稳定性的影响至关重要。 完全并行的高阶有限元技术将用于研究粘弹性流体的许多二维和三维自由表面和界面流动原型。 具体来说，这项工作将重点研究混合剪切/拉伸流中流体弹性引起的流动变化，以及研究流体弹性和非平衡能量对此类流动稳定性的影响。 特别令人感兴趣的是确定导致混合运动流中粘弹性不稳定性的机制，这种不稳定性在聚合物和复合材料的加工中经常遇到。